<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>UserHeader</title>
</head>
<body>
<div class="user-avatar">

</div>

</body>
<style>
  .user-avatar {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-bottom: 100px solid cornflowerblue;
    position: relative;
  }
  .user-avatar:after {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 100px solid cornflowerblue;
    position: absolute;
    content: "";
    top: 30px;
    left: -50px;
  }
</style>
</html>